The present invention relates to a control apparatus and its failure analysis, particularly to the technology for analyzing control apparatus failures by recording whether the failure in the control apparatus is caused by increases in temperature due to an internal element failure in the control apparatus itself or by increases in temperature due to a system failure.
The configuration in prior art was such that as described in, for example, Japanese Application Patent Laid-open Publication No. 2000-267522, after the temperature of the control apparatus has been monitored using temperature sensors, when the detected temperature is higher or lower than a predetermined temperature that has been set as the judgment criterion, that state is detected as trouble and the control apparatus itself stores the corresponding trouble information or issues a warning to the user by use of a display unit.
The above-described prior art has the problem that for example, if the gradient of the temperature increases existing during trouble is too steep, the memory media themselves become damaged during storage of the corresponding trouble information into the control apparatus itself and consequently, the trouble information cannot be saved.
The prior art also poses the problem that when a failure in the control apparatus is analyzed, it cannot be judged whether the failure was caused by an abnormal ambient temperature or by trouble with the internal elements of the control apparatus itself.
The object of the present invention is to supply a control apparatus which, even if the temperature gradient is too steep, can save the required information in the memory media of the control apparatus or analyze whether the failure was caused by an abnormal ambient temperature or by trouble with the internal elements of the control apparatus itself.
In order to attain the above object, the internal temperature of the control apparatus and the ambient temperature thereof are monitored and if the difference between these temperatures oversteps the required temperature range, trouble information will be stored into the memory media of the control apparatus. Also, the required relationship on the temperature difference between the internal temperature of the control apparatus and the ambient temperature thereof is considered to judge whether the failure was caused by an abnormal ambient temperature or by trouble with the internal elements of the control apparatus itself.